Let's Make Robots!

What's better for a robot? huge or small

I would like to share some opinions about what is better for you:

A small robot or a huge robot?

I'm building robots since 2008, now the only one i am working on is really big.

I mean it is 13Kg of weight and 1.25m of height, it can speech through the shield for the arduino who acts as mainboard and has a lot of room to add really cool stuff just by using i²c(for example). It has two sonars, a pseudo-hand and nice coloured leds, powerful actuators, current sensors and it is built almost 90% with metal...BUT i was thinking about tearing it apart.

You know, robotics costs money and "you can't always get what you want"..And i want a sumo robot!

is about a year that i am working on this robot,i named it Venerdì.You know, a robot after some time makes us attached to it and i really need your hopinions since you are the only ones competent enough to say something about it knowing what you mean!

the robot is for indoors and is a "little" oversized for sumo (it sounds like a paradox :) )

Indoors and huge is not the best combination, anyway it moves pretty well in a room.

What would you do if you have the same materials on your workbench? a big or a small robot?

(i don't have a photocamera, i'll ask a friend for a photo if you want to see it)

Sorry for my bad English.

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Now i can remember, it was Serv-O bot the one who given me the idea to build a robot like this! It was awesome so i decided to make also a big one.

It is made of metal just cause i was tired of hot-glue that goes dumpish in summer, so i decided to make it as modular as possible with nuts and bolts and i also wanted it as heavy as possible, something like a challenge with my building skills :)

Was started with wood but i was tired of using drill every second so i decided to use metal bars with holes.

Now i'm making it 3D in blender to use with morse simulator (nice to have a virtual lab for a big robot), so i will ask my friend for a photograph because i also need it to make it feel like the real one with proportions.

I also use to have a development log since i begin to build it, it has some photographs but i found there were into the hard disk i lost recently, just one survived and it was in really early stages (it is also not finished yet).

Here was the Alpha stage:

firs version

This is the only old photograph i have, i will upload a newer soon!

Now it has real motoreductors instead of servos and it has now rollerblade wheels. The only thing not changed is the "arm" (this crappy thing attached on the left of the picture should be an arm).

the strange white clouds are just because there was some disorder in the room i would not like to share :)

There is to say, a robot like the one in this photo is not so good for home because of its width, a taller robot it could navigate more like a human with legs: tight in the base and bigger near the top.

Another good thing about the big robots is the time can stay powered, as it was here it could be idler for about 60 hours or so, cause of the big battery.

Yes, it costs a lot. I used all of my robot budget last year to buy the motoreductors but remember i used nuts and bolts? So if some day i want it, i can rebuild everything without run the risk of ruining anything. It is like a very huge knex kit, and i really love this thing, cause the money i spent is not dropped in trash until the things i bought will last.And are really heavy duty.

If you want your robot to be able to roam around your home, it will need to be large enough to make the transition from vinyl floors to carpeted areas.

BOE-Bot sized robots are too small to do this well.

I also think it's nice if the robot is large enough to be seen so someone doesn't accidentally step on it. Something a little smaller than a Roomba would probably be large enough to be noticed easily.

It's also nice it the robot doesn't take up too much room. You want to be able to get past the robot without having to squeeze by.

You want to be careful that the robot isn't so large and heavy as to cause damage to the floors. 

I think Maxhirez's Serv-O bot is about as large as one would want a home robot to be.

I have a household robot I'm slowly building. Most of the robot will be down by the floor but I'm planning on have some part of it stick up high enough to interact with humans. I'm also hoping I can get the robot to move up and down stairs on its own. (I'm sure this is easier said than done.)

I'm hoping I can use the robot to remotely inspect the house while I'm away. I'll probably add some moisture detectors to it so it can find leaking water.

I think most of my robot will be made from plastic so it shouldn't be as heavy as your robot. I agree that larger robots require more expensive parts. The motors and controllers end up costing a lot more on a larger robot.

Because of the extra cost of large robots, I tend to try to build the smallest robot that can do the job intended for it.

My household robot will need to be larger than most of my other robots since I want it to be able to climb stairs.

Please have your friend take a picture of your robot. I'd really like to see it.

I agree with you, a home robot if intended as quite as possible like the tv ones must be big and nice to see.

This makes the robot appear much more smart than it is.Personally i prefer an ugly but smart robot than a cool looking not-so smart one.

My robot was born to be "multipurpose", it now has some routines like wall following, a "cleaning" mode (it turns like mad in both directions and tries to avoid obstacles),  a "guard" mode that puts into sleep while a CDS is not changing value, a built-in air sanitizer and stuff like that.But i have no more ideas on what to make it do and lots of PIC micro waiting to be used...the arduino is just for voice recognition and usb debug of everithing in the BUS. Is a very modular robot.It is also glueless, all nuts and bolts.

My question is(if you ever start planning a robot without having a fixed objective ex. line follower etc): for a "multipurpose" robot, did you prefer to make a small or big robot?

the robots i made before were something like 20x25cm but it was too easy to fill up all the room for components and very difficult try keeping a clean looking.

Smaller robots can run without running the risk of seriously damage someone or something if a bug appears or accidentaly shorting some cable. It could happen. It happened to me with this big one, broken oscilloscope probe and scratches on my hand. Nothing serious but enough to add current sensing to avoid the motors to spin while hitting things (like my hand) and fuses to try avoiding burnings(should be there also in smaller robots). So in that way, the smaller the better. Another pro of a small robot is agility enabling it to run in very tiny spaces.

There is also to say that the cost of  the actuators is big as the robot, but the big robot if well built and planned, also has pratical pros, like the more weight it can carry, including a Pb battery, a laptop running cv and various ideas who came while bulding is in process.

i also have another question: what is for you the most important side of the robot project? (i don't know if i written it the right way)

for example:

the most important thing in a project of mine is the cost of components and the learning i gain building/coding it and obviously the fun. :)


A robot's size should be determined primarily by its purpose. If all you want is a toy that demonstrates some emulation of mobile life, then a little desktop runner need not be much larger than your hand and possibly as small as a coin. If you want the robot to bring you drinks or answer the door, it will have to be larger. That said, in the eighties when companies like Heathkit, RB Robotics and Androbot first started to try to roll out the first wave of home robots, they all were .5 m to 1m in height but were not a great deal more sophisticated than an Arduino SHR with a SpeakJet shield. However, it was their size and appearance (and to a lesser extent some of the routines and games they played) that really held the attention of the kids in the classrooms that they visited.